The proposal – passed by 82 votes to 24 – was fiercely opposed by Russia and Iran, allies of the Syrian regime, which stands accused of using chemical weapons throughout the seven-year-long civil war.

Moscow, too, has been accused of violating international laws on chemical weapons. Britain pointed the finger at Russia for the March 2018 poisoning of former double agent Sergei Skripal and his daughter in Salisbury, southern England. It is a charge that the Kremlin has strenuously denied.

Earlier on Wednesday, the Russian embassy in the Netherlands said Britain had failed to provide “any hard evidence for the so-called ‘Skripals case’” in a fiery Twitter post.

The embassy tweeted that the British government had “embroiled their allies in the blatant campaign against Russia. Now they try to drag the #OPCW in their games at the 4th special session of the CSP”.

“Deception” is perhaps the word of a day. Has the UK 🇬🇧 presented any hard evidence for the so-called “Skripals case”? No. They embroiled their allies in the blatant campaign against 🇷🇺. Now they try to drag the #OPCW in their games at the 4th special session of the CSP pic.twitter.com/n1zd2L95tw

Before the proposal was voted on, Iran, Venezuela, Kazakhstan and Belarus had attempted to table four amendments, which were duly defeated.

"Belarus' amendment to the Decision we and others tabled to strengthen @OPCW would have gutted it and made it impossible to identify the perpetrators of CW attacks," British ambassador Peter Wilson said in a tweet.

Use of chemical weapons is illegal under international law. However, they have been used more commonly since 2012, mainly in Syria, but also in Iraq and Malaysia, where the VX nerve agent was deployed in the assassination of North Korean leader Kim Jong Un’s half-brother.

Prior to the vote, the OPCW, which oversees a 1997 treaty banning the use of toxins as weapons, had the technical expertise to assess what chemical weapons were used, but it did not possess the powers to name the perpetrator.

The responsibility of apportioning blame for chemical weapons attacks in Syria had previously been held by a joint UN-OPCW team, known as the Joint Investigative Mechanism, from 2015 to 2017.

But Russia used its power of veto on the UN Security Council to stop the body’s mandate being extended and it was disbanded in November last year.

Wednesday’s diplomatic victory for Britain, which needed a two-thirds majority to succeed, will allow the OPCW to pick up where the disbanded body left off.